https://bugs.kde.org/show_bug.cgi?id=380307
--- Comment #5 from quazgar <quaz...@posteo.de> --- Thank you for reminding me! I actually had tried all the authentication methods before posting the bug already. Before the upgrade to Exchange 2016, the connection used to work with SSL/TLS on port 993 and plain authentication. One server-side change which was announced was that from this version on, the username would no longer be the email address but of type "$domain\$user" (the Microsoft specific user name convention), for example "gwdg\foobar". Another user here found out that this did not help at all, but what did help was to replace the correct backslash by a normal slash (which is not supposed to work). So what worked for her was "gwdg/foobar". Maybe that is an excessive interpretation of the backslash as an escape character? I also tried this variant but unfortunately ran into the problem that KMail/Akonadi started running into an infinite loop with automatic filtering of messages, see the attached screenshot. I am not sure if this has to do with my using of Thunderbird as an intermediate solution (not sure if it was connected to the same IMAP account simultaneously or not) or if this is linked to the original problem. Anyways since Akonadi did not stop to duplicate these messages, the only way for me to keep a working computer was to disable the account in KMail and use Thunderbird for the time being. -- You are receiving this mail because: You are watching all bug changes.